1. Field Of The Invention
The present invention relates to the art of material surface finishing by grinding. More particularly, the present invention relates to machinery for finishing the surface of extremely thin strips of wood veneer.
2. Description of the Prior Art
The objective of wood veneering includes the lamination of a thin slice of expensive, furniture grade wood to the face of a structural substrate to obtain the esthetic, grain and texture surface qualities of the expensive wood. Such veneer slices may be as thin as 0.025 inch, in random widths up to 24 inches and in random lengths up to 10 feet.
A 0.025 inch thickness strip of natural wood has very little structural rigidity perpendicular to the surface planes against which any finishing forces are to be applied. Additionally, a 0.025 inch thickness provides a very small margin of error by power tools having no "feel" for how much material is being removed from a single location during the finishing process.
Accordingly, the gap between the cutting edge of the finishing tool and a rigid support surface for the flimsy material within that gap must be precisely controlled to prevent variations in the final veneer thickness.
Also necessary to a uniform surface finish of natural veneer strip is a uniform feed rate to the finish cutting tool so that each increment of the surface is subjected to the same degree of tool working as all other increments.
Driven belt fed surface finishing machines such as represented by U.S. Pat. No. 3,178,860 to J. N. Clyne and U.S. Pat. No. 2,958,163 to F. E. Cammerzell, Jr. are well known to the prior art. The operative principle of such prior art machines is to continue the material carrying feed belt between a supporting bed surface and the cutting tool. Any compliance within the flexible feed belt or between the belt and the support surface therefore is reflected in a variance between the finishing tool and the worked material surface.
It is, therefore, an object of the present invention to provide a continuous belt fed veneer finishing machine having a precisely controllable gap setting between the machine cutting tool and a rigid bed surface.
Another object of the present invention is to provide a drum grinding finishing machine wherein the drum tool may be quickly withdrawn from the bed plate to expedite abrasive replacement.
Another object of the present invention is to provide a precisely adjustable abutment surface for a veneer surface grinding drum to regulate the depth of grinding cut within 0.001 inch.
Another object of the present invention is to provide a replaceable, flexible strip abrasive surface for a grinding drum having no transverse irregularities to the cylindrical continuity of the drum.